MAPT and Alzheimer disease: Training and internal cross-validation cohorts were drawn from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and the Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) Study subset of the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s (A4) Study (ADNI-A4 training; n=1250 MRI-tau PET image pairs; 684 clinically unimpaired, 228 clinically impaired).